>>> welcome back to "newsline." i'm meeky yamamoto in tokyo. >>> saudi arabia and other gulf nations have begun air strikes in yemen. >>> authorities are looking into the link between an extremist group and the gunmen who carried out the fatal museum attack. and french investigators are analyzing audio from a german airliners cockpit voice recorder to try to figure out why it crashed. >>> saudi military officials are making moves to protect their border in what they call yemen's legitimate government. they launched military operations in the capital sanaa with a newly formed coalition of gulf-region allies. the say the air strikes are to counter rebel forces that drove out their president. saudi airplanes have targeted houthi strongholds. they dropped bombs on the